Issue #13725: regrtest does not recognize -d flag.

Patch by Erno Tukia.
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index cd76541..38d7b25 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -298,7 +298,7 @@
 
     support.record_original_stdout(sys.stdout)
     try:
-        opts, args = getopt.getopt(sys.argv[1:], 'hvqxsoS:rf:lu:t:TD:NLR:FwWM:nj:Gm:',
+        opts, args = getopt.getopt(sys.argv[1:], 'hvqxsoS:rf:lu:t:TD:NLR:FdwWM:nj:Gm:',
             ['help', 'verbose', 'verbose2', 'verbose3', 'quiet',
              'exclude', 'single', 'slow', 'random', 'fromfile', 'findleaks',
              'use=', 'threshold=', 'trace', 'coverdir=', 'nocoverdir',
diff --git a/Misc/ACKS b/Misc/ACKS
index 02742af..2559ab3 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1004,6 +1004,7 @@
 John Tromp
 Jason Trowbridge
 Anthony Tuininga
+Erno Tukia
 Stephen Turner
 Theodore Turocy
 Bill Tutt